A generally employed structure of an on-board motor module is the one storing and fixing the module in a housing, so that resistance to vibration or shock is improved.
As one example of such a structure, Japanese Patent Laying-Open No. 9-200991 discloses a technique in which a motor winding is connected by means of welding to a terminal block mounted at a terminal end integrally with a housing and the connected portion is molded, so that resistance to vibration or shock is improved.
In order to connect a motor module to a terminal block, a mechanism for absorbing an error within a tolerance related to size, plumbness, mounting position and the like of each component of the terminal block or the motor module (hereinafter referred to as “component tolerance”) is required. In general, the component tolerance can be absorbed by connecting a longer motor winding to allow slack.
However, when the motor module is mounted in a narrow space, as the distance between the stator of the motor module and a terminal block is small, the degree of freedom of the motor winding is small and it is difficult to absorb the component tolerance by the motor winding.
If the motor module is connected to the terminal block in a state where the component tolerance is not fully absorbed, a stress may be applied to the motor winding of which insulation has been ensured by the varnish treatment, and a failure such as loss of the ensured insulation may be caused. On the other hand, if each component tolerance is just strictly set in order to better assemble the motor module to the terminal block, the costs may be increased.